Why is there a screeching sound when braking?

[JoyLee]

There are several reasons for the screeching sound when braking: 1. Worn brake pads are one of the causes of friction noise during braking. If the brake pads have been used for a long time, the backing plate will gradually lose its material. This causes metal to come into contact with other metal, resulting in a screeching noise; 2. Poor-quality brake pads often contain metal chunks that rub and scrape against the rotor surface, causing severe damage and generating noise; 3. Components can accumulate dust, and dust and dirt are normal. However, sometimes small stones or other solid objects on the road may get stuck between the brake caliper and rotor, whether the brake is pressed or not, causing brake friction noise; 4. When the brake shims are damaged, they will produce friction noise. Worn shims will come into contact with the braking system (such as the rotor), and when metal meets other metal, they will emit a screeching sound from the braking system; 5. Not driving frequently is another reason why a car makes friction noise when braking. The average lifespan of brake pads is 20,000 kilometers. Leaving the car parked in a garage for weeks without attention, combined with harsh weather, can cause the rotor to rust and corrode.

[MaggieFitz]

The other day when I was driving home, I suddenly heard a screeching sound while braking, which scared me and made my heart race. I remember my friend's car had the same issue before, and he said it was because the brake pads were worn too thin, causing the metal part to directly rub against the brake disc, which produced that kind of screeching noise. Check your car—maybe you brake too frequently or have been driving long distances, accelerating the wear. Go to the shop as soon as possible; don’t delay like I did last time, which ended up costing me more to repair the brake disc. Also, the noise tends to be more noticeable on rainy days because moisture causes the brake pads to rust, and adding lubricant won’t help—the key is to replace the worn parts promptly. Safety comes first! Whenever you hear noise while braking, stay alert and don’t let a small issue turn into a big problem.

[LaEllie]

I've been fixing cars for over a decade and have encountered many cases of brake squealing. The main issues usually lie in brake pad material problems or contamination with impurities, like when sand and gravel get stuck in the gaps after rain, causing friction noise when braking. A simple test: gently apply the brakes a few times. If the noise diminishes, it's probably just dirt; if it persists, the pads might be worn thin. Remember to check the brake discs for scratches, as they can worsen the problem. Regular cleaning of the brake system can prevent this – no need for professional tools, any roadside shop can do it. That piercing noise isn't just annoying, it affects braking performance too. Addressing it early saves money and hassle – don't wait until components are damaged to act.

[DiBrantley]

Thinking back to driving vintage cars in my youth, the braking sounds weren't as shrill. Modern car materials are different and more prone to abnormal noises. Piercing sounds often mean the brake pad wear indicator is working, signaling it's time to replace parts. My neighbor complained about loud noises last week, which turned out to be misalignment during installation causing uneven friction. I suggest you get it checked when possible - mechanics can measure thickness with a gauge. Avoid sudden braking in daily use to extend pad life. Don't delay when the sound appears; spending a little to replace pads is wiser than repairing the entire brake system. After all, driving safety is personal responsibility - never cut corners.